Moscow: Russian courts on Wednesday ordered several people to spend New Year's Eve in jail after a protest in support of top Kremlin critic Alexei Navalny, who was convicted of fraud in a controversial trial.

About 250 people were detained at a Moscow protest called by Navalny yesterday after a judge sentenced him and his younger brother Oleg to three and a half years in prison.

His sentence was suspended while Oleg Navalny was ordered to serve his term in a penal colony, infuriating the prominent opposition leader.

Most of those detained were released after several hours but about 70 spent the night in police cells and have to face the courts on charges of resisting police demands and participating in an unauthorised rally, rights organisation OVD-Info said.

RIA-Novosti news agency reported from one court that two activists were sentenced to 15 days of detention.

Navalny, 38, himself defied his house arrest to join the protest.

Policemen grabbed him off the street and put in a van before he could reach the protest on Manezhnaya square near the Kremlin but took him home rather than to the police station.

He later wrote on his Twitter blog that five policemen remain on the stairwell outside his apartment and that the drive to his apartment building has been blocked.

The Navalny brothers were convicted of defrauding French cosmetics company Yves Rocher and embezzling 27 million rubles (more than half a million dollars at the exchange rate at the time), although the firm has said that it suffered no damages.

News of the verdict was absent from programmes on the main television channels, where most Russians get their information.

Police said about 1,500 people turned up for the Moscow rally yesterday, although Navalny's supporters gave higher figures.

Although observers had predicted that Navalny's violation of his house arrest would lead to a tough punishment and possibly jail, a court today said it will not be reviewing the complaint filed by the prison service over the infraction.

Navalny's defence also asked the court to repeal the house arrest - which was imposed during the fraud trial and recently extended to February - arguing that his suspended sentence means he should be free to move around.

Several people braved freezing temperatures for hours after the protest was broken up by huddling in a giant chrismas ornament sculpture on the square - including Pussy Riot member Maria Alyokhina - and were briefly detained today.